'Information known'

"Whilst we continue to work to try and establish the motive for this murder, I firmly believe there are people in the community who have important information that will assist the investigation."

He said officers from the specialist Trident unit and the local borough of Hackney will be in the Hindrey Road area over the weekend asking witnesses to come forward.

One of the suspects seen running from crime is described as a black man while the other is light-skinned, possibly of Asian or Turkish appearance, police said.

They headed towards the Pembury Estate.

A post-mortem examination showed Joseph died from a gunshot wound to the head.

His 22-year-old older brother has since been discharged from hospital after he was also shot while his twin, who was in the back of the car with Joseph when the shooting happened at about 20:20 GMT, was not injured.